In which sentence is all CAPITALIZATION correct?

If you don't want to help me with the assignment, I'll just do it …………

The graduate student------------- did our exams is quite young.

Helen has studied Biology ...... six months. She really enjoys it.

I'm sorry to make you ...... your project again, but it's not good enough.

In England, many children… ............. wear school uniforms; they can't come to school if they don't.